what made the difference and what makes a difference in a case like this in the 21st century and the technology to isolate these photographs. >> all right, former fbi profiler clint van zant. we just want to bring viewers up to speed on where things stand right now. a number of developments. a tremendous amount of activity over the course of the last few hours and here's where things stand at this time. one of the suspects in the boston marathon bombing is dead at this time. one of suspects at large. that suspect was referred to as suspect number two, shown in photos wearing the white cap and fishlts say that he's believed to be armed and dangerous. they're advising the public to use extreme caution and advising massachusetts residents to stay indoors and not answer their doors. a human toll here, one police officer was killed overnight in a shootout with this man. story. stay with us for more. >>> good morning. lester holt in watertown, massachusetts, after a dramatic night, the two men suspected of carrying out the marathon bombing in boston on monday have apparently led police on a wild chas